Democrats received 59 million votes
Republicans received 57 million votes

2008 House of Representatives Election:

Democrats received 64 million votes
Republicans received 51 million votes.

So, these Republicans that stayed at home for McCain also stayed at home for Romney and 10 percent of people who previously voted for Democrats voted for Republicans, but Obama's support levels only dropped from 53% to 51%?

Right.

What's even more interesting, is the type of Republicans that lost their seats. It was the moderates.